1. Field of the Invention
The invention relates to a device for alignment of machine shafts.
2. Description of Related Art
A device for aligning machine shafts is known from U.S. Pat. No. 4,463,438, inventor Zatezalo. The device of this patent calls for the use of mechanical measurement means. Accordingly, the attainable accuracy in the alignment of machine shafts is limited and depends on various mechanical boundary conditions, for example, on the slack of the measurement means.
A similar device with much improved accuracy is described in European Patent EP 0145745 of Lysen. Instead of mechanical measurement indicators, EP 0145745 calls for those based on a laser beam. In this way, the utility of shaft alignment instruments was radically enhanced. Overall, the microelectronics and measurement methods provided in each case enabled computer-aided, accurate and much more comfortable alignment of measurement shafts than had been possible in the past. However, to date, the innovative devices of this type have had the disadvantage that various activities must be performed manually before or after the actual measurement process. This relates especially to the input of various parameters, such as, for example, dimension data which must be input manually into the pertinent computer system. Another manual activity consists in manually converting the computed correction values, i.e., shifting or calibrating at least one machine in three directions of space, for which in part a certain expenditure of force is necessary. Although there are suggested solutions for the latter problem, so far there has not been any solution for automating and making more efficient the initial inputting of machine dimensions. This invention solves this special problem.
According to the invention, a device for aligning two machine shafts which are coupled to one another has:
at least one laser light source for emitting laser light
at least one reflector for reflecting the laser light
at least one receiving device for receiving the laser light
a first arithmetic means for determining parallel and angular offset of the machine shafts
an evaluation and arithmetic means for determining the distance of the machine mounting elements relative to the plane of symmetry which lies between the machine shafts and which intersects the axes of the machine shafts essentially vertically.
Typically, there are two separate laser light transmitting and receiving means, specifically, one for determining the amounts of offset on the shafts, and one for determining the distances of the machine mounting elements among one another or relative to a plane of symmetry which lies between the machine shafts. In one special embodiment of the invention, there is only a single laser light transmitting and receiving means which is used alternately for the indicated determinations of amounts and distances.
Characteristic of the invention is the procedure of automatically supplying the electronically determined distances between the machine mounting elements to the computing process for determining the correction values with which the displacement values are computed using which optimum alignment of the participating machines and machine shafts can be achieved. Accordingly, it is possible to combine the indicated first arithmetic unit and the indicated evaluation and arithmetic means for determining the distance from the machine mounting elements in a single electronic circuit. This electronic circuit can be functionally connected to a single operating surface (as the output device) and a single input device. In this way, it is now possible to carry out the measurement process which was carried out manually in the past for determining dimensions with computer support, by which the inadvertent introduction of measurement error is clearly reduced and the alignment measure is simplified overall.
The invention is suitable for use in alignment devices with different designs. These alignment devices can therefore provide a single laser beam for determining the amounts of shaft offset, or two separate laser beams.
In the indicated determination of distances on an electronic basis, to some extent, triangulation processes or transit time measurements can be used. In transit time measurements, comparatively simple reflectors which are located on likewise simply designed stands can be used.
The invention is explained in detail below with reference to the accompanying drawings.